Since about 1952, there has been sporadic interest in the use of cement concrete as an electrical insulator and recently this interest has quickened primarily because of economic pressures brought about by the rise in cost of conventional porcelain and epoxy insulators.
Concrete is a mixture of an aggregate and a binder which can be cement or a polymer, or both. A major problem in the use of concrete as an electrical insulator is the difficulty in constructing an insulator which has sufficient resistance to high humidity. Moisture is the single most deleterious component which affects the properties of a polymer containing concrete and even what seems to be an insignificant amount of residual moisture, i.e., about 0.2% or less, can adversely effect the electrical properties.
Recently, great strides have been made in the construction of a polymer concrete having appropriate electrical properties for use as an insulator. However, it has been found that such new materials are still plagued by the problem of water absorption with the passage of time under high humidity conditions such as those encountered on the Gulf Coast of the United States.
Accordingly, it is the object of this invention to provide a polymer containing electrical insulation grade concrete in which moisture absorption under high humidity conditions with the passage of time is greatly reduced. This and other objects of the invention will become apparent to those skilled in the art from the following detailed description.